Sewing thread



NOV. 15, 1960 w, s WOQDSON, JR 2,959,910

SEWING THREAD 2 Sheets-Sheet 1 Filed Dec. 23. 1955 vIN VEN TOR. WML/mw S. Manso/v Ja rfrfow Nov. 15, 1960 Filed Dec. 23. 1955 w. s. wooDsN, JR 2,959,910

SEWINGy THREAD 2 Sheets-Sheet 2 INVENTOR. WML/4M S. h/ooDsO/vrf?.

TTOP/VE Y United States Patent O SEWWG THREAD William S. Woodson, Jr., Ridgewood, NJ., assigner to The Manhattan Shirt Company, New York, N.Y., a corporation of New York Filed' Dec. 23, 1955, Ser. No. 555,067

11 Claims. (Cl. 57-153) The. present invention relates generally to an improved yarn and in particular it relates to an improved shrinkproof sewing thread.

In the manufacture of textile and fabric articles, it is generally necessary to sew or stitch together fabric panels in partially or entirely overlapped (either side-by-side or superimposed) relationship. It has been found, when the fabric has low shrinkage characteristics and a conventional sewing thread is employed, that puckering occurs along the seams following the laundering ofy the fabric article. This condition is highly undesirable, particularly in the case of articles of apparel such as shirts and blouses, since the puckering greatly detracts from appearance of the garment and all too often reduces the size and dimensions of the garment, thereby afecting its tit. This puckering is experienced not only with fabrics formed of synthetic yarns such as nylon, acrylic fibers and other synthetic fibers and blends of natural and synthetic fibers, but also with fabrics of many natural fiber yarns such as co-tton and the like, particularly where the fabrics are shrunk. It is believed, as one` possibility, that the puckering is a result of the differential shrinking of the conventional sewing thread, which is normally formed of cotton, and the stitched fabric. The sewing thread, upon washing, shrinks to a considerably greater extent than the sewn fabric panels, drawing the latter into a puckered condition in the vicinity of the line of stitching.

Another undesirable condition encountered `as a consequence of the shrinking of a sewing thread is in the manufacture of mens shirt collars where woven fabrics have been widely used. Mens shirt collars are made up, of a plurality of several parts of shrunk fabric, cut to predetermined configuration and then stitched together with al sewing machine by the use of usual sewing thread. The industry found, although such collars were made of shrunk fabrics, they were reduced to an undesirable extent, one-half size moreV or less than the cut size of the collar. Such reduction was due to contraction of the sewing thread. In an attempt to correct such condition, most collar manufacturers normally cut collars about onehalf size larger thank the rated size, as stamped upon the Collar, in the expectation that the collar, when washed, would shrink to the size stamped thereon, which was, ofcourse, the size which the user expected the collar to retain during use. Experience also showed that when the collars were washed, and contraction occurred in spite of the use of shrunk fabric, the fabric would gather or pucker along the lines of stitching. lt could not always be predetermined accurately how much contraction would take place during washing and therefore the oversize allowance was usually a hit or miss estimate.

1t is thus a principal object of the present invention to provide an improved thread that will overcome this undesirable feature.

Another object of the present invention is to provide an improved sewing thread.

A further object of the present invention is to provide an; improved. sewing threadv characterized by a minimum of shrinkage consequent to the washing of the thread.

Still a further object of the present invention is to provide an improved sewing thread capable of producing seams which do not pucker upon laundering thereof.

Another object of the present invention is to provide an improved sewing thread which may be satisfactorily employed in high speed sewing machines and which produces a seanrwhich does not pucker upon laundering even when applied tol low shrinkage fabrics formed of synthetic or natural fibers.

Still another object of the present invention is to provide an improved method for producing an improved sewing thread possessing the characteristics Iabove set forth.

The above and other objects of the present invention will: become apparent from a reading of the following description taken in conjunction with the accompanying drawings, wherein Figure l is a graph illustrating the eiiect of yarn twists on elongation of the washed improved thread under different loading conditions as compared to the length of' unwashed thread;

Figure 2 is a graph illustrating the effect of finishing twists` on elongation of the washed thread under dilerent loading conditions` as compared to the length ofxun'- washed thread;

Figure 3 is a graph illustrating the effect of the `amount of polyvinyl alcohol' sizing pick-up by the yarn on elongation of the washedthread under diiferent loading condi'- tions as compared to the length of the unwashedv thread;

Figure 4 is a graph illustrating the effect of tensionl during the iinishing twistingoperation on elongation of the washed thread under diiierent loading conditions asv compared to the length of the unwashed thread; and

Figure 5 is a front view illustrating asewing thread embodying theV present invention.

It has been discovered that a multiple ply sewing thread formed of al plurality of ply yarns highly twisted together, each of said ply yarns being highly twistedandV treated with a solublezsizing or bonding material, possesseshighly desirable properties and is particularly useful in. stitching together fabric layers or panels. Such a sewing' thread does not shrink upon being washed but, on the contrary, extends in length under very low tension conditions and receives a set below which it will not return. As a result, material sewn with such thread will not gather or bel compressed, yand seams formed with the improved thread do not pucker as with usual sewing thread, a con dition generally resulting when low shrinkage fabricsI are sewn with conventionalthread. The advantages in em'- ploying this improved type of thread are numerous and y apparent.

lt has also been foundthat the improved thread possesses superior extensibility characteristics when the in'- dividual plies are sized and dried under minimum tension conditions. and the sized plies likewise twisted together under minimum tension conditions. The construction, of the sewingthread, in `accordance with the present invention, may be similar to that of a conventional sewing thread. It may be formed of two or more plies or ends with each of the plies or ends being highly twisted; the plies in turn may be singlings or multiple ply. In case of the multiple ply ends, the sizing may be applied to the twisted ends or to the twisted individual singlings. The singling or end -twist should be in excess of 10 turns per inch, which herein defines the llower limit of a high twist. Superior results, however, are obtained when the singlings have a twist multiplier of between 3 and 4, for example, about 3.4 and the finishing has a twist multiplier of between 4 and 8, for example, about 6.7. The singling or end twist and the finishing twist should be in opposite senses, the one right or left and the other respectively left or right.

Any suitable removable finish may be used, but a sizing or bonding soluble in or removable by straight water or alkali containing water is preferred. When the term water soluble sizing is used herein, it applies also to sizing material or bonding material which forms a suspension in water rather than being dissolved therein. Examples of suitable sizing and finish materials are polyvinyl alcohol of sizing grade, carboxy-methyl-cellulose, starch, alcohol soluble nylon, etc. The sizing should be applied to the singlings or ends in such concentrations and under such conditions that they carry a minimum of 5% by dry weight of the sizing material and, preferably more, between and 25%. It has been found that polyvinyl alcohol sizing in excess of about 25%, based on the weight of the yarn, does not contribute significantly to the thread properties.

In manufacturing the improved thread, the highly twisted singlings are produced on a spinning frame in the usual manner. The yarns are then passed through a conventional padder which includes a pair of vertically spaced rotated drums adjustably spring urged toward cach other, the bottom surface of the lower drum being immersed in the sizing solution of the required concentration. The yarns travel about the bottom of the lower drum through the bite and about a portion of the upper drum. The amount of sizing pickup is adjusted by the drum pressure of the spring or may be adjusted by the concentration of the sizing solution. The yarn then travels through a drying oven and withdrawn therefrom by a pair of rollers, which deliver the dried, sized highly twisted singling yarns to winding devices. The speed of the delivery rollers is adjusted so that a minimum of tension is applied to the drying yarns compatible with the operation of the machine. The speed is preferably such that the yarn traversing the drier is in the shape of a shallow catenary. It is important to the realization of highly superior qualities that a low tension be maintained during this drying step and that the sized yarns be thoroughly dried before being wound or packaged. It should be understood that other types of conventional equipment may be employed in applying the sizing provided a low tension may be effected as well as drying before packaging or winding. For example, a Winder with an emulsion roller may be used.

The dried sized twisted singlings or ends are then ply twisted on a conventional ring twister in an opposite direction. Here again, it is important for optimum results that the finishing twist be applied at a low tension, preferably at a minimum tension compatible with the efficient operation of the twisting devices. The value of such minimum tensions are well known to those skilled in the art. Any well known lubricant such as wax or the like is then applied to the nished thread in the usual manner.

A sewing thread produced in accordance with a preferred embodiment of the present invention was formed of three ends of 56s yarns, each having a right twist of about 26 turns per inch. Polyvinyl alcohol sizing was applied to the individual twisted singlings, which were then dried and packaged. Three ply sewing threads having different finishing twists were produced; the twists being l0 turns per inch, 24 turns per inch and 30 turns per inch respectively. Lengths of the threads were washed and dried and the resulting lengths were measured both under different loads and following removal of the respective loads. The results were as follows:

Extension in inches per yard 56s 3 ply thread, singlng twist 26 l.p.i.

l0 t.p.i. 24 t.p.i. 30 t.p.i. Finishing Twist, Grams Load ,'Teu- Rc- Ten- Re- Tenltc- Sion laxed sion laxed sion hured if s 1/f o iff l if u l 'if u 1 s 5/e life 19s my Ttu 25/16 14/lu mts 19in its 3Lifo 3%; ggfs 3T/fu 294s 51/a lia It is apparent from the above table that, with a sized singling having a twist of 26 turns per inch and with a finishing twist as low as l0 turns per inch, the resulting thread extends upon washing. Moreover, the amount of extension, both under loaded and relaxed conditions, increases with increased finishing twist.

The graph illustrated in Figure 1 of the drawing demonstrates the effect of varying the twists of the singlings upon the elongation of the washed and dried thread consequent to removal of the sizing as compared to the length of the unwashed thread. The threads tested consisted of three 56 singlings with the right twists as indicated and plied with a finishing twist of 30 turns per inch, left. The sizing employed was polyvinyl a1- cohol. In the graph, the full lines indicate threads having yarn twists of 22, 26 and 30 turns per inch, right respectively, the yarns being sized and dried prior to the finishing twist. The broken line curves indicate the elongation properties of thread having the same construction as the threads indicated in full line except that the individual singlings were not sized. It is important to observe that in the case of the threads having the individual sized singlings, an elongation was effected upon washing even under no significant load. In the case of the singlings having a twist of 22 turns per inch, the elongation varied from about 2 inches under no appreciable load to more than 4 inches under a loading of grams. In contrast to this, threads of similar construction, but with no sizing of the individual singling, exhibited no elongation over their original unwashed length for loads under approximately 40 grams tension. It is also interesting to note that the elongation of the thread increased as the singling twist decreased. It should be noted that in the illustrated graphs and the tests associated therewith, the washed and dried tested threads had an original unwashed test length of 36 inches and that the elongation is measured relative to said unwashed length.

i The graph shown in Figure 2 of the drawing illustrates the effect of the finishing twist on the elongation of the washed and dried improved thread. Here again, the thread tested consisted of three 56 singlings having 26 turns per inch, right. The full line curves indicate finishing twists of 15, 24, 30 and 34 turns per inch, left, respectively, wherein the singlings have been individually sized and dried and the broken line corresponds to a thread having a finishing twist of 34 turns per inch, left, wherein the individual singlings have not been sized. In the cases of the threads containing the sized singlings, an elongation over the unwashed thread following washing and drying was experienced under load conditions in excess of about 25 grams. In the case of the improved thread having a finishing twist of 34 turns per inch, an elongation of about 1/2 inch was experienced under no significant loading and an elongation of 2*/2 inches under a load of about 155 grams. In contrast to this, in the thread of the corresponding construction, in which the singlings were unsized, at about 50 grams load, no elongation was exhibited. It is also interesting to note that the greater the finishing twist, the greater the elongation upon washing and drying over the original length of the unwashed thread.

The graph of Figure 3 of the drawing illustrates the eiect of the amount of sizing in the form of polyvinyl alcohol picked up by the individual singlings on the elongation of the improved thread upon washing and drying under diiferent conditions of loading. 'The thread tested was constructed of three plies of 56 singlings, 26 turns per inch, right, having a finishing twist of 30 turns per inch, left. The individual singlings carried by weight 11.5%, 16% to 18%, 31% to 32% and 22% to 26% polyvinyl alcohol. It is interesting here to note that the maximum elongation was exhibited by the thread whose singlings had a pick-up of 22% to 26% polyvinyl alcohol. Increasing the amount of sizing pick-up above this resulted in a decrease in the thread elongation following washing as illustrated by the curve for the thread having a 31% to 32% pick-up. Furthermore, the elongation following washing was less with a decrease in the sizing pick-up below 22%.

The family of curves indicates that there is an appre ciable increase in the elongation following washing and drying of the various threads as the tension during sizing and drying is decreased. However, even where the tension during sizing is as high as 50 grams, there is an elongation following washing and drying exhibited even under minimum loading conditions.

The graph shown in Figure 4 of the drawing illustrates the effect of tension during the application of the iinishing twist to the'thread on the elongation under varying loads following the washing and drying of the thread. The thread tested consisted of three plies of 56 singlings, 26 turns per inch right, with a finishing twist of 30 turns per inch, left. The full line curves represent the improved threads with finishing twists applied under tensions of 12 grams, 25 grams and 70 grams respectively, whereas the broken line curves represent threads without sized singlings with tensions applied during application of the finishing twist of 7 to 13 grams, 13 to 22 grams and 70 grams. Here again, it should be noted that with a reduced tension applied during the application of the finishing twist, the elongation following washing and drying of the thread increased in the improved yarn. Even with a high tension of 70 grams during the nish twisting, under a 25 gram load, the washed and dried thread returns to substantially its original length. However, threads of similar construction and twisted under similar conditions where the singlings were not sized, even under minimum twist tension at as high as 35 grams load, the washed thread did not return to its original unwashed length.

In Figure 5 of the drawing, T designates a three-ply sewing thread as described above, formed of highly twisted singlings E, bonded or sized while in a twisted state with a suitable material S as aforesaid.

The various constructions of the thread and the manner of producing them have been previously described. It may include two or more singling plies or ends E, for example, 2, 3, 4, 5, 6, etc. Furthermore, the ends E may likewise be formed of two or more highly twisted singlings highly twisted together. Moreover, a reverse twist may be :imparted to the sized twisted singlings prior to the plying thereof. Another variation is the application of a second suitable water removable sizing to the nished thread Without substantially disturbing the sizing carried by the singlings.

The present invention may be applied to any sewing thread formed of staple bers, particularly those exhibiting shrinkage properties such as cotton, nylon, etc. The examples of sewing thread given above were formed of cotton but the same structures may be applied to the other staple liber yarns.

While there have been described and illustrated preferred embodiments of the present invention, it is apparent that numerous alterations and omissions may be made without departing from the spirit thereof.

I claim:

1. A multiple ply sewing thread comprising a plurality of highly twisted yarns individually bonded subsequent to twisting with a removable bonding material and thereafter highly twisted together to form said sewing thread and characterized after being washed and dried by its extensibility under low tensions to a greater amount than its original unwashed length, said yarns containing between 10% and 25% by weight of said bonding material.

2. A multiple ply sewing thread comprising a plurality of highly twisted yarns individually bonded in said twisted state with a removable bonding material constituting at least 10% by weight of said yarns, said individually bonded twisted yarns being highly twisted together to form said sewing thread which is characterized, after being washed and dried, by its extensibility under low tensions to a greater length than its original unwashed length.

3. A multiple ply sewing thread in accordance with claim 2, wherein said bonding material is selected from the class consisting of polyvinyl alcohol, carboxy-methylcellulose, starch and alcohol soluble nylon.

4. A multiple ply sewing thread in accordance with claim 2, wherein said yarns are singlings.

r5. A multiple ply sewing thread in accordance with claim 2, wherein said yarns have been dried after bonding under substantially relaxed conditions.

6. A multiple ply sewing thread in accordance with claim 2, wherein said yarns have been twisted together under low tension.

7. A multiple ply sewing thread in accordance with claim 2, wherein said yarns have a twist multiplier between 3 and 4.

8. A multiple ply sewing thread in accordance with claim 2, wherein said sewing thread has a finishing twist multiplier of between 4 and 8.

9. A multiple ply sewing thread in accordance with claim 2, wherein said yarns are formed of staple fibers.

10. A multiple ply sewing thread in accordance with claim 2, wherein said yarns are formed of cotton.

11. A multiple ply sewing thread in accordance with claim 2, wherein said yarns are singlings having a twist multiplier of approximately 3.4 and said sewing thread has a finishing twist multiplier of approximately 6.7.

References Cited in the le of this patent UNITED STATES PATENTS 1,538,030 Dreyfus May 19, 1925 2,638,734 Cruz May 19, 1953 2,663,989 Schlatter Dec. 29, 1953 2,714,758 Woodson Aug. 9, 1955 2,731,788 Donaldson Jan. 12, 1956 FOREIGN PATENTS 546,743 Great Britain July 29, 1942 693,223 Great Britain June 24, 1953 

